A pie chart drawn up by Windows 7 engineers shows how much each part of your laptop draws from your slowly-discharging battery. Check out where a typical Windows system spends its juice below.

The Windows 7 team, of course, says it wants to knock back the upcoming OS' draw on systems through a number of tactics: Better processor-speed scaling, "trigger-starts" for background processes, auto-suspension of idle USB devices, and more power-control offerings for third-party software and peripherals. They also promote using sleep/suspend mode more often than actual shutdowns to speed up start-ups, but given that Windows 7's beta seems to boast boot-up times less than 30 seconds, that's more a matter of personal patience (and battery condition).